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  • Cluster Fly Flies

    Cluster Fly
  • Cluster Fly
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Elimination

The first step is to make the structure as airtight as possible by roasting or caulking the main entry routes used by flies. It is important to identify access points such as window frames, vents, cracks or openings around ducts.

Indoors, Maheu&Maheu Glue Traps can be installed near windows and light sources, where flies tend to gather.

In attics or structural voids, these insects can hide in large numbers. It is therefore recommended to regularly check these spaces and remove dead flies using a vacuum cleaner, since their cadavers can attract other insects, such as larder dermestes.

Finally, to prevent infiltration in the fall, it is useful to carry out waterproofing work before the end of summer, ideally around mid-August, during which time flies seek to enter buildings to spend the winter.

If the sealing cannot be done efficiently and we do not want to tolerate them inside, the intervention of our certified technicians remains a safe and effective solution.

Actions

  • Place glue traps near windows where you see activity
  • Request assistance from one of our pest management experts

Prevention

  • Seal the outsides of windows, doors, eaves, chimneys, etc. as completely as possible

Description and development

The Cluster Fly (Pollenia rudis F. ) is a holometabolous insect of the Diptera order and the Calliphoridae family. It is bigger (8 to 10 mm) than the House Fly and other flies encountered indoors. Its thorax is dark gray, and young adults have yellowish or golden hairs like the color of pollen, which explains their Latin name. At rest, the Cluster Fly’s wings fold over each other and the fly’s back. When squashed, these flies emit a smell similar to buckwheat honey.
Cluster Flies are frequent pests in homes and commercial buildings, where they hibernate from fall to spring. Each spring when the ground thaws and grass starts to grow, the flies leave their winter refuge to breed, laying eggs one by one in the ground. Larvae emerge from the eggs three days later, burrow into the ground, and penetrate an earthworm to feed. Once they have finished growing (after 13 to 22 days), they emerge from the ground and turn into pupae. The pupal stage lasts 11 to 14 days, which brings the total life cycle to about 33 days. There can be 3 or 4 generations per summer, depending on soil humidity, temperature, and other conditions.

Habits

These flies usually live outside, where they feed off flowers, fruit, and sometimes tree sap. When seeking shelter for the winter, they can fly distances of more than 2 km. They congregate in great numbers in the walls of selected buildings with the greatest sun exposure. They get inside through structural defects and other available openings. Once there, they cluster together in attics, walls, and other hollow spaces in the structure, which is why they are called Cluster Flies.

These flies are easy to tell apart from House Flies by their behavior. They are very attracted to ultraviolet sunlight and often buzz around in windows. An ordinary electric light can also attract them-they can flit for hours around a lampshade or fluorescent lights.

Their behavior is unpredictable. Sometimes they will walk right on your face and fall into your coffee mug for no apparent reason. Fortunately, they do not breed indoors. In nature they hibernate in hollow trees under the bark as well as in rock crevices.

In colder rooms, these flies can remain dormant right until spring. However, those that have taken refuge in warmer spots can emerge at any point during the winter and cluster in the windows. Between spring and fall, they spend all their time outdoors.

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